[joseG86]

Definitive tube setup for me:
RCA 22DE4, Tungsram E80CC and GM 6V6 (made by RCA)

This is the closest sound to HA-6A with GL KT88 in triode mode. I tried 5 different 6v6 tubes and the differences aren't very obvious except for the GMs which makes classical music sound very real and very detailed but detailed without any harsh or fake/sharp sound, it is very sweet

Music used for testing:

A New World: Intimate Music from Final Fantasy (Full Arranged Album)​

 

[AudioPowerHead]

Definitive tube setup for me:
RCA 22DE4, Tungsram E80CC and GM 6V6 (made by RCA)

This is the closest sound to HA-6A with GL KT88 in triode mode. I tried 5 different 6v6 tubes and the differences aren't very obvious except for the GMs which makes classical music sound very real and very detailed but detailed without any harsh or fake/sharp sound, it is very sweet

Music used for testing:

A New World: Intimate Music from Final Fantasy (Full Arranged Album)​

Nice ! Just a word of caution on usage of e80cc tubes on the 12au7 sockets. @Andykong has repeated his advice in the other thread that it is not suitable for ha-6a. You might want to check whether it is suitable for ha-3a.

 

[Bkido]

Nice ! Just a word of caution on usage of e80cc tubes on the 12au7 sockets. @Andykong has repeated his advice in the other thread that it is not suitable for ha-6a. You might want to check whether it is suitable for ha-3a.

I only dared to run the E80CC after getting the confirmation from Cayin that it'd safe to run them in the HA-3A.

 

[Daiyama]

If somebody is interesseted in trying these out, I have a pair of Phillips E80CC SQ=Special Quality for sale. For info just PM.

 

[ThanatosVI]

Music used for testing:

A New World: Intimate Music from Final Fantasy (Full Arranged Album​

Great music

 

[joseG86]

I only dared to run the E80CC after getting the confirmation from Cayin that it'd safe to run them in the HA-3A.

Thanks for that, I'm using E80CC w/o any fear because of you and I'll never regret it haha

Great music

Volume 2 is great as well, available in Qobuz/Tidal with much much better quality

Nobuo Uematsu is an amazing composer along with many others like Naoshi Mizuta or Masayoshi Soken

 

[Andykong]

I only dared to run the E80CC after getting the confirmation from Cayin that it'd safe to run them in the HA-3A.

Since there are mixed responses regarding E80CC, we had a thorough discussion regarding the technical feasibility of this vacuum tube as a replacement for 12AU7 on our vacuum tube headphone amplifiers. After checking the specification in detail, Chen DeHai, our Chief Engineer confirmed that E80CC can be used in HA-6A and HA-3A. The E80CC will draw more heater current, which might affect the long terms tear and wear of the amplifier slightly, but it is technically safe in HA-6A and HA-3A, it won't blow the amplifier or damage the transformers.

We won't add E80CC to the recommended tube replacement table in our product manual. In our past experience, this will introduce a misunderstanding that E80CC is a direct replacement of 12AU7 and can be used as a replacement in all other tube amplifiers (including speaker amplifiers) when they can't find any reference to E80CC in their product manual.

Sorry for the miscommunication in the past, we hope this will clarify the situation.

 

[MokhaMark]

Hi All, I will only link this here once so as not to spam the thread again, but in case any HA-3A owners are interested:

https://www.head-fi.org/classifieds/tubes-for-cayin-ha-3a.38093/

 

[Andykong]

Minor Revision on Cayin HA-3A

Due to supply chain problems, we have to revise our HA-3A vacuum Tube Headphone Amplifier as follows:

• Output Tube: from matched pair JJ 6V6S to matched pair Electro Harmonix 6V6GT
• Rectifier Tube: from RCA 22DE4 to RCA 25AX4GT

The EH 6V6GT and JJ 6V6S are compatible, user can swap their JJ 6V6S to EH 6V6GT or vice versa.

While the 25AX4GT and 22DE4 look very similar to each other, they are not compatible tubes. The filament of 22DE4 is 22.4V, therefore in our early HA-3A productions, the power supply from our power transformer to the rectifier tube filament (22DE4) is 23V. On the other hand, the filament of 25AX4GT is 25V, we have to revise the corresponding power supply to 25V in order to facilitate an optimized feed to the 25AX4GT. The change is not significant, so if you install a 25AX4GT to the 22DE4-based HA-3A or vice versa, it won't blow up and it probably can work in the short term. However, we must clarify upfront that this will likely damage your vacuum tube and operate your amplifier in less than optimized condition, Cayin does NOT RECOMMEND this.

As always, we have etched the corresponding vacuum tube product code on the top plate of the amplifier. If you notice the V5 position is marked as 25AX4GT, that means your HA-3A required a 25AX4GT as rectifier tube, please do not install a 22DE4 vacuum tube as a replacement. Alternatively, if your HA-3A has marked 22DE4 for V5, please do not install 25AX4GT as a replacement rectifier tube.

Last but not least, both early and new HA-3A production batches will offer the same audio performance, and we have made our best effort to maintain a similar sound signature after the revision.

 

[Renexx]

Minor Revision on Cayin HA-3A

Due to supply chain problems, we have to revise our HA-3A vacuum Tube Headphone Amplifier as follows:

• Output Tube: from matched pair JJ 6V6S to matched pair Electro Harmonix 6V6GT
• Rectifier Tube: from RCA 22DE4 to RCA 25AX4GT

The EH 6V6GT and JJ 6V6S are compatible, user can swap their JJ 6V6S to EH 6V6GT or vice versa.

While the 25AX4GT and 22DE4 look very similar to each other, they are not compatible tubes. The filament of 22DE4 is 22.4V, therefore in our early HA-3A productions, the power supply from our power transformer to the rectifier tube filament (22DE4) is 23V. On the other hand, the filament of 25AX4GT is 25V, we have to revise the corresponding power supply to 25V in order to facilitate an optimized feed to the 25AX4GT. The change is not significant, so if you install a 25AX4GT to the 22DE4-based HA-3A or vice versa, it won't blow up and it probably can work in the short term. However, we must clarify upfront that this will likely damage your vacuum tube and operate your amplifier in less than optimized condition, Cayin does NOT RECOMMEND this.

As always, we have etched the corresponding vacuum tube product code on the top plate of the amplifier. If you notice the V5 position is marked as 25AX4GT, that means your HA-3A required a 25AX4GT as rectifier tube, please do not install a 22DE4 vacuum tube as a replacement. Alternatively, if your HA-3A has marked 22DE4 for V5, please do not install 25AX4GT as a replacement rectifier tube.

Last but not least, both early and new HA-3A production batches will offer the same audio performance, and we have made our best effort to maintain a similar sound signature after the revision.

Looks like 25AX4GT rectifier tubes are same availability like 22de4 for tuberolling.

Someday I will write an comparison for my different 22de4 tubes. Definitely a great way to tune your amp.

 

[heyguyslol]

Minor Revision on Cayin HA-3A

Due to supply chain problems, we have to revise our HA-3A vacuum Tube Headphone Amplifier as follows:

• Output Tube: from matched pair JJ 6V6S to matched pair Electro Harmonix 6V6GT
• Rectifier Tube: from RCA 22DE4 to RCA 25AX4GT

The EH 6V6GT and JJ 6V6S are compatible, user can swap their JJ 6V6S to EH 6V6GT or vice versa.

While the 25AX4GT and 22DE4 look very similar to each other, they are not compatible tubes. The filament of 22DE4 is 22.4V, therefore in our early HA-3A productions, the power supply from our power transformer to the rectifier tube filament (22DE4) is 23V. On the other hand, the filament of 25AX4GT is 25V, we have to revise the corresponding power supply to 25V in order to facilitate an optimized feed to the 25AX4GT. The change is not significant, so if you install a 25AX4GT to the 22DE4-based HA-3A or vice versa, it won't blow up and it probably can work in the short term. However, we must clarify upfront that this will likely damage your vacuum tube and operate your amplifier in less than optimized condition, Cayin does NOT RECOMMEND this.

As always, we have etched the corresponding vacuum tube product code on the top plate of the amplifier. If you notice the V5 position is marked as 25AX4GT, that means your HA-3A required a 25AX4GT as rectifier tube, please do not install a 22DE4 vacuum tube as a replacement. Alternatively, if your HA-3A has marked 22DE4 for V5, please do not install 25AX4GT as a replacement rectifier tube.

Last but not least, both early and new HA-3A production batches will offer the same audio performance, and we have made our best effort to maintain a similar sound signature after the revision.

Do you have an ETA on when the new revision will be available?

I had planned to get a 2nd unit for my office as I have plenty of backup replacement 22DE4 tubes. I'd prefer to have the original version for my 2nd unit so I don't have to hunt down more replacement tubes. I would imagine any resellers with current stock have the OG version. Would I be correct on this assumption?

 

[jamato8]

Minor Revision on Cayin HA-3A

Due to supply chain problems, we have to revise our HA-3A vacuum Tube Headphone Amplifier as follows:

• Output Tube: from matched pair JJ 6V6S to matched pair Electro Harmonix 6V6GT
• Rectifier Tube: from RCA 22DE4 to RCA 25AX4GT

The EH 6V6GT and JJ 6V6S are compatible, user can swap their JJ 6V6S to EH 6V6GT or vice versa.

While the 25AX4GT and 22DE4 look very similar to each other, they are not compatible tubes. The filament of 22DE4 is 22.4V, therefore in our early HA-3A productions, the power supply from our power transformer to the rectifier tube filament (22DE4) is 23V. On the other hand, the filament of 25AX4GT is 25V, we have to revise the corresponding power supply to 25V in order to facilitate an optimized feed to the 25AX4GT. The change is not significant, so if you install a 25AX4GT to the 22DE4-based HA-3A or vice versa, it won't blow up and it probably can work in the short term. However, we must clarify upfront that this will likely damage your vacuum tube and operate your amplifier in less than optimized condition, Cayin does NOT RECOMMEND this.

As always, we have etched the corresponding vacuum tube product code on the top plate of the amplifier. If you notice the V5 position is marked as 25AX4GT, that means your HA-3A required a 25AX4GT as rectifier tube, please do not install a 22DE4 vacuum tube as a replacement. Alternatively, if your HA-3A has marked 22DE4 for V5, please do not install 25AX4GT as a replacement rectifier tube.

Last but not least, both early and new HA-3A production batches will offer the same audio performance, and we have made our best effort to maintain a similar sound signature after the revision.

Is the rectifier change trickling to the other amps that use the 22DE4 with a change to the 25AX4GT?

 

[Andykong]

Do you have an ETA on when the new revision will be available?

I had planned to get a 2nd unit for my office as I have plenty of backup replacement 22DE4 tubes. I'd prefer to have the original version for my 2nd unit so I don't have to hunt down more replacement tubes. I would imagine any resellers with current stock have the OG version. Would I be correct on this assumption?

When we receive new orders from our dealers, we'll ship out the new production batch of HA-3A with Electro Harmonix 6V6GT and RCA 25AX4GT. The new HA-3A is available in mainland China as we speak, but the current stock on hand of oversea Cayin dealers are the JJ 6V6S and 22DE4 versions.

 

[Andykong]

Thanks for being such an important part of the Cayin community. Hope you have a great Christmas and New Year!

 

[Steve Wilcox]

Am I right in thinking the Electro Harmonix tubes are Russian?